Butylated hydroxyanisole or 2-butyl-4-methoxyphenol is an accepted antioxidant which has found commercial use in the food industry. Generally, butylated hydroxyanisole is in the form of a white crystal with a melting point of about 64.degree. C. and is insoluble in water. In addition, hydroxyanisole and/or BHA have found use as starting materials for the manufacture of antioxidants, pharmaceuticals, plasticizers, dye stuffs, and as a stabilizer for certain hydrocarbons.
Heretofore, numerous synthetic routes have been used to produce BHA or alkylated hydroxyanisoles. For example, U.S. Pat. No. 2,887,515 teaches the preparation of BHA by alkylation of tertiary butyl hydroquinone with dimethyl sulfate. The tertiary butyl hydroquinone is prepared from hydroquinone as taught by U.S. Pat. No. 2,722,556. Alternatively, hydroquinone can be methylated to give p-hydroxyanisole as taught in British Pat. No. 1,277,186 or British Pat. No. 1,450,296 and alkylated with isobutylene to give BHA. Both of the above processes require expensive hydroquinone as a starting material and require a selective methylation. The present invention provides a process for the production of alkylated hydroxyanisoles which utilizes as a starting material a waste stream from a process for the production of hydroquinone. In addition, the instant invention is directed to a process that overcomes the selectivity problems associated with processes used heretofore.